title: Nanoparticle-driven orientation transition and soft-shear alignment in diblock copolymer films via dynamic thermal gradient field.
abstract: Sharp dynamic thermal gradient (∇T ≈ 45 °C mm(-1)) field-driven assembly of cylinder-forming block copolymer (c-BCP) films filled with PS-coated gold nanoparticles (AuNPs; dNP ≈ 3.6 nm, φNP ≈ 0-0.1) is studied. The influence of increasing AuNP loading fraction on dispersion and assembly of AuNPs within c-BCP (PS-PMMA) films is investigated via both static and dynamic thermal gradient fields. With φNP increasing, a sharp transition from vertical to random in-plane horizontal cylinder orientation is observed due to enrichment of AuNPs at the substrate side and favorable interaction of PMMA chains with gold cores. Furthermore, a detachable capping elastomer layer can self-align these random oriented PMMA microdomains into unidirectional hybrid AuNP/c-BCP nanolines, quantified with an alignment order parameter, S.
authors.affiliation: Department of Polymer Engineering, The University of Akron, Akron, OH, 44325, USA.
authors.forename: Ren
authors.initials: R
authors.lastname: Zhang
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Singh
authors.forename: Alei
authors.initials: A
authors.lastname: Dang
authors.forename: Lu
authors.initials: L
authors.lastname: Dai
authors.forename: Michael R
authors.initials: MR
authors.lastname: Bockstaller
authors.forename: Bulent
authors.initials: B
authors.lastname: Akgun
authors.forename: Sushil
authors.initials: S
authors.lastname: Satija
authors.forename: Alamgir
authors.initials: A
authors.lastname: Karim
mesh_terms: D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D011108:Polymers / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry
chemical_list: D011108:Polymers; D011137:Polystyrenes; C522519:poly(styrene-block-methyl methacrylate); D006046:Gold; D019904:Polymethyl Methacrylate
keywords: aligned nanostructure; block copolymers; composites; nanoparticles; zone annealing